1. Field of the Invention
The present invention relates to a shielding terminal to be connected with an end of a shielded cable. The invention also relates to a method for mounting a shielding terminal to a shielded cable.
2. Field of the Invention
A known shielding terminal is shown in FIGS. 8 and 9 and is provided with an inner terminal xe2x80x9caxe2x80x9d to be connected with a mating terminal, an outer terminal xe2x80x9ccxe2x80x9d accommodating the inner terminal xe2x80x9caxe2x80x9d and a dielectric element xe2x80x9cbxe2x80x9d provided therebetween. The inner terminal xe2x80x9caxe2x80x9d is crimped into connection with an end of a core xe2x80x9cexe2x80x9d of a shielded cable xe2x80x9cdxe2x80x9d, and the outer terminal xe2x80x9ccxe2x80x9d is crimped into connection with ends of a braided wire xe2x80x9cfxe2x80x9d and a sheath xe2x80x9cgxe2x80x9d of the shielded cable xe2x80x9cdxe2x80x9d. Such a shielding terminal is disclosed in Japanese Unexamined Utility Model Publication No. 5-27983 and other publications.
The shielding terminal of FIGS. 8 and 9 should have a sufficiently large fastening force to ensure that a pulling force on the shielded cable xe2x80x9cdxe2x80x9d does not detach the shielded cable xe2x80x9cdxe2x80x9d from the terminal. Conventionally, biting blades project from the outer surface of the inner terminal xe2x80x9caxe2x80x9d. The biting blades bite into the inner surface of the dielectric element xe2x80x9cbxe2x80x9d to prevent detachment.
However, the conventional shielding terminal has a groove formed in the inner surface of the dielectric element behind the biting blades. The groove prevents the dielectric element from exerting a sufficient force to prevent the detachment. Thus, there is a demand for a further improvement.
The present invention was developed in view of the above, and an object of the invention is to provide a shielding terminal and a mounting method that allows a larger fastening force of the shielding terminal to a shielded cable.
The invention is directed to a shielding terminal for connection with an end of a shielded cable. The cable has a core and a shield layer surrounding and spaced from the core. The shielding terminal comprises an inner terminal to be connected with the core of the shielded cable and an outer terminal to be connected with the shield layer of the shielded cable. The outer terminal accommodates the inner terminal with a dielectric element provided between the inner and outer terminals. At least one metal lock is formed in an outer surface of the inner terminal, and at least one locking hole is formed in an inner surface of the dielectric element for engagement by the metal lock.
Detachment of the connected inner terminal and core from the dielectric element is prevented effectively by fitting and engaging the metal lock into the locking hole. As a result, a fastening force of the shielding terminal to the shielded cable can be strengthened.
The metal lock preferably is formed by making at least one cut in the outer surface of the inner terminal and bending the cut portion.
The metal lock preferably projects obliquely backwards when seen in a direction of insertion of the inner terminal into the dielectric element.
The inner surface of the dielectric element preferably is formed with at least one filling portion that contacts the outer surface of the inner terminal for partly filling a clearance between the inner surface of the dielectric element and the inner terminal. The mere fitting of the metal lock into the locking hole makes the inner terminal likely to shake in the dielectric element. However, in the present invention, the filling portion fills the clearance, and hence the inner terminal is prevented from shaking. This, in turn, prevents fine sliding movements and abrasion between the inner terminal and a mating terminal.
The inner terminal may be formed with at least one resilient or elastic contact piece for contacting a mating terminal. The filling portion fills the clearance in a direction substantially parallel to an elastic deforming direction of the contact piece. The filling portion preferably is on an inner surface of the dielectric element facing the contact piece.
The inner terminal may be a female terminal with an elastic contact piece that undergoes an excessive elastic deformation due to forces exerted by a tab of a mating male terminal shaken in a direction parallel to the elastic deforming direction. However, in the present invention, the clearance is filled in the direction parallel to the elastic deforming direction of the contact piece. Thus, the inner terminal is prevented from shaking in the same direction, and the elastic contact piece will not undergo an excessive elastic deformation.
The at least one filling portion preferably comprises at least one projection that projects from the inner surface of the dielectric element.
The outer terminal preferably has an outer metal locking portion engageable with an auxiliary locking hole on an outer surface of the dielectric element for locking the dielectric element in the outer terminal.
The invention also is directed to a method for mounting, connecting or assembling a shielding terminal with an end of a shielded cable. The method comprises connecting an inner terminal with a core of the shielded cable, and connecting an outer terminal with a shield layer of the shielded cable while accommodating the inner terminal with a dielectric element provided between the inner and outer terminals. The inner terminal is locked with the dielectric element by engaging at least one metal locking portion formed in an outer surface of the inner terminal with at least one locking hole formed in an inner surface of the dielectric element.
The metal locking portion may be formed by making at least one cut in the outer surface of the inner terminal and bending the cut portion.
The method may further comprise the step of at least partly filling a clearance between the inner surface of the dielectric element and the inner terminal with at least one filling portion on the inner surface of the dielectric element for contacting the outer surface of the inner terminal.
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings.